An all wheel drive (AWD) system of a vehicle usually comprises a power take-off unit, a propshaft and a rear drive module. The power take-off unit is attached to the powertrain (i.e., the engine and the transmission), and transmits the driving force from the transmission to the rear wheels. The driving force to the rear wheels is transmitted, as stated above, from the engine to the power take-off unit and further to the propshaft and the rear drive module, which distributes the driving force to the rear wheels of the vehicle.
The means for transmitting the driving force from the power take off unit to the propshaft is usually established by an output shaft of the power take-off unit being connected to the propshaft. This connection is commonly established by providing the connecting ends of the propshaft and the output shaft, respectively, with a flange. The connection is thereafter established by interconnecting the flanges with several bolts.
A vehicle of today is an advanced construction and the available space for the different components constituting the vehicle is limited. Therefore, there exists a risk of conflicts between the different parts of the vehicle. Due to the highly competitive environment in the vehicle industry, it is desirable to be able to assemble a vehicle in a fast manner and with high quality. Therefore, since conflicts between different parts tend to increase the complexity of assembly and hence increase the time necessary for assembly, and also potentially lower the quality of the assembled vehicle, there exists a need to have certain clearances between the different parts of the vehicle during the assembly operation. The avoidance of conflicts with other components of the vehicle may be especially relevant for heavy components such as an all wheel drive system, since heavy components are more difficult to guide and fit into place for an assembler. Furthermore, also because it is time consuming, and also because it is potentially dangerous for the assembler, there is a need that the assembler does not have to access components hidden behind other components when assembling the vehicle.
A power take-off unit with a flange and bolt connection of the propshaft and the output shaft of the power take-off unit for an all wheel drive vehicle does not always meet these needs.
Therefore, it is at least one aim of the present invention to provide an all wheel drive system for a vehicle where the power take-off unit and the interconnection between the propshaft and the output shaft of the power take-off unit meets these needs (i.e., that provides sufficient clearance to other components when assembling the vehicle), that is able to limit the time needed to assemble it, and also that does not require hidden parts of the interconnection to be accessed for assembling purposes. In addition, other aims, desirable features, and characteristics will become apparent from the subsequent summary and detailed description, and the appended claims, taken in conjunction with the accompanying drawings and this background.